If you have ever watched television during the weeknight evening hours or had your regular radio programming interrupted by some messages from the sponsors, it is likely that you have been inundated with a slew of advertisements for antacids and acid-suppressing drugs, including the "purple pill" (Nexium), Prilosec, Prevacid, Pepcid AC, Zantac, and numerous other medications that lower stomach acid. Understandably, you may be under the impression that the symptoms of heartburn, indigestion, and gastrointestinal acid reflux disease (GERD) are caused by too much stomach acid. As acid-suppressing drugs are among the most commonly used prescription and over-the-counter medications, the pharmaceutical companies are banking on acceptance of the idea that stomach acid is something that needs to be kept in check. However, in the reality that is not controlled by the powerful pharmaceutical industry and the conventional medical system (both of which have an interest in keeping you ill and dependent on medications), stomach acid is not something to be feared! It is much more likely that your symptoms are being caused by low stomach acid, instead of an overproduction of stomach acid.
Why stomach acid is important

In the infinite wisdom of the human body, the stomach was designed to produce the acid that is necessary for proper digestion of food. When functioning properly, the parietal cells of the stomach secrete hydrochloric acid that bring the stomach pH to a range of approximately 1.5 to 3.0. This is strong enough of an acid that if it were to be dropped on a piece of wood, it would burn a hole through the wood. The inner lining of the stomach is protected from its own acid by a thick layer of mucous and epithelial cells that produce a bicarbonate solution (an alkaloid) to neutralize the acid.

Stomach acid has several important roles including:

Breakdown of proteins into a form that they can be digested (called proteolysis).

Activation of the enzyme pepsin, which is responsible for protein digestion.

Inhibiting the growth of microorganisms that enter the body through food to prevent infection.

Proper absorption of many minerals, such as calcium, magnesium, zinc, and manganese.

Signaling when the food (referred to as chyme) is ready to leave the stomach and move into the small intestine for continued digestion.

When the digestive system is functioning normally, food travels down the esophagus to the stomach. The stomach works to ensure adequate mechanical digestion (by churning of the stomach) and production of stomach acid until the chyme is brought to the proper pH level. At that point, the valve at the lower end of the stomach, the pyloric sphincter, is triggered to open and release the chyme into the small intestine. The pH level of the chyme entering the small intestine triggers the release of pancreatic enzymes (to continue with the digestive process) and sodium bicarbonate (to neutralize the chyme to prevent burning of the small intestine).

What happens when stomach acid is too low

When stomach acid production is low, dysfunction throughout the digestive system can occur, leading to numerous symptoms and disease processes. The body's preference is to keep the chyme in the stomach until it reaches the proper pH level. Therefore, when stomach acid production is low, the chyme sits in the stomach for a longer period of time without the nutrients being broken down properly. At the same time, the low stomach acid promotes an environment that is more friendly to the growth of microorganisms, which are fed by the carbohydrates that become fermented from sitting in the stomach for too long. Eventually, excessive pressure from the bacterial overgrowth and maldigested food results.

The stomach has two valves, the lower esophageal sphincter (LES) (at the top of the stomach) and the pyloric sphincter (at the bottom of the stomach). While the pyloric sphincter is a one way valve, the LES is designed to open both ways. When excessive pressure builds up in the stomach, but the pH is still not at an optimal range to allow opening of the pyloric sphincter, the body identifies only one option to release the pressure: Open up the LES. Opening of the LES allows release of the pressure into the esophagus and that is what commonly leads to the symptoms of heartburn and acid reflux. Even if your stomach isn't producing enough acid, any amount of acid going into the esophagus will result in uncomfortable symptoms because the esophagus is not designed to handle stomach acid. Frequent opening of the LES toward the esophagus will contribute to a weakened valve that compounds the problem.

Low stomach acid also contributes to digestive problems downstream from the stomach in the small intestine. If the stomach is not able to produce enough acid to bring the pH level of the chyme to an optimal range, after a while, the stomach will be forced to move it through the pyloric sphincter into the small intestine. Because it is not at the proper pH, the chyme does not trigger the release of sodium bicarbonate, which can result in duodenal ulcers. The higher pH of the chyme also does not trigger the release of pancreatic enzymes. The small intestine is not able to break down the chyme properly and the large, undigested particles of food can begin to have a negative impact on the lining of the small intestine. The lining becomes more permeable and allows the undigested food particles to enter the bloodstream where your body's immune system recognizes them as foreign invaders. This triggers a systemic immune response that can lead to food sensitivities, inflammation, and autoimmune disease. This phenomenon is known as leaky gut syndrome.

Some undigested food particles may continue into the large intestine. This malabsorbed food can lead to a disruption of the normal gut flora (see this post for the importance of gut flora to health and the immune system). The large intestine may become inflamed and subject to a variety of conditions, such as constipation, diarrhea, or irritable bowel syndrome. The disruption of the normal gut flora also impacts your overall immune system and can lead to autoimmune conditions.

Prevalence and symptoms of low stomach acid

Low stomach acid is a common problem in developed nations. According to Jonathon Wright, MD (author of "Why Stomach Acid is Good for You"), approximately 90% of Americans produce too little stomach acid. He arrived at this conclusion after measuring the stomach pH of thousands of patients in his clinic. (While conventional medical doctors sometimes measure esophageal pH levels in particularly difficult cases of acid reflux, they never measure stomach pH levels. As mentioned above, any amount of acid in the esophagus is abnormal and will cause symptoms.)

Because low stomach acid has such a profound impact on overall health, symptoms may affect a variety of body systems and result in conditions that include:

Hopefully, by now, it should be clear that covering up symptoms of heartburn, indigestion, and acid reflux by lowering stomach acid production even more through the use of acid-suppressing drugs, is not an effective, safe, or smart way to address the root cause of low stomach acid.

In part II of this series, I will discuss how to address low stomach acid holistically through the healing power of real foods and natural supplements. Stay tuned!